Windscreen wiper

ABSTRACT

[The present invention is based on a] A windshield wiper having a wiper arm, which is made up of a mounting part and a hinge member including an integrated wiper rod [( 26 )] having a u-shaped cross-section profile, and on which a wiper blade [( 12 )] pivots via a retaining spring[( 22 )]; the side walls [( 76, 78 )] of retaining spring [( 22 )] being connected by an open hub [( 66 )] for a hinge pin [( 20 )] and which guide the wiper rod [( 10 )] on the outside by their projecting inner walls. The [It is proposed that the] u-shaped cross-section profile extends to the free end of the wiper rod[( 10 )], and [that], in the end region, in side flanges [( 32, 34 )] of the cross-section profile located across from one another, at least one crosspiece-pair [( 38, 40 )] is preformed, at least one of which being provided with a flap [( 44, 46 )] bent toward the inside, the retaining spring [( 22 )] engaging by at least one longitudinally positioned plug [( 70, 74 )] between the strips of a crosspiece-pair [( 38, 40 )] and locking into place on the wiper rod[( 10 )].

BACKGROUND INFORMATION

[0001] The present invention is based on a windshield wiper according to the preamble of claim 1.

[0002] Known windshield wipers have a wiper arm, which is made up of a driven mounting part and a hinge member, which is connected to it via a hinged joint. The mounting part and the hinged part usually have a u-shaped cross-section profile that is open toward the vehicle windshield. Additional components are expediently located in the interior space of the profile. Located in the interior space of the cross-section profile of the hinge member, for instance, is an extention spring, which prestresses the hinge member with the mounting part. In some exemplary embodiments, water lines and/or spray nozzles of a windshield-washer system are also accommodated in the unshaped cross-section profile of the hinge member.

[0003] A hinge member is known from German Patent 198 15 171 A1 in which the front area of the integrated wiper rod is folded over several times and bent in the shape of a hook. This requires several method steps in the manufacture. Furthermore, exposing galvanized sheet material to heavy 180° bending carries the inherent risk that the tin coating will tear and/or detach in the heavily deformed areas. Furthermore, due to the low height of the material accumulation in the area of the hook, the moment of resistance against bending and torsion is relatively low, so that the wiper rod elastically deforms in response to pressure, and tends to rattle.

[0004] The wiper blade is usually equipped with a bracket assembly and a wiper strip retaining it. The hook of the wiper rod engages with a retaining spring, which is mounted by an open hub on a hinge pin of a center clip of the bracket assembly and is used as an adapter and bearing part between the wiper strip and the wiper blade. The hinge formed in this manner and the bracket assembly allow the wiper strip to adapt to a curvature of the vehicle windshield. In order to laterally guide the wiper blade, the retaining spring, on the one side, is guided along its lateral walls between two side flanges of the center clip and, on the other side, along the lateral surfaces of the engaged wiper rod. However, the lateral surfaces are relatively small. Therefore, they are subjected to high loads and wear out quickly, so that the wiping quality rapidly decreases due to poor guidance of the wiper blade.

[0005] In order to be able to exchange a worn wiper blade, the wiper blade is rotated at an approximately 90° angle, and the retaining spring is pulled out of the hook in the longitudinal direction. This is awkward, especially with relatively long hooks, since the installation space for sliding the rotated wiper blade in the longitudinal direction toward the vehicle windshield is limited.

[0006] From the German Patent 195 37 854 A1, it is known to a join a wiper arm and a wiper blade using a retaining spring. At least one finger, angled in the direction of the vehicle windshield at the free end of the wiper rod, engages in a positive locking manner with a corresponding guide shaft of the retaining spring. In the guide shaft, the bent finger is retained by an automatic detent device, which is preformed on the retaining spring. A slight rotation is sufficient to exchange the wiper blade, enabling the detent device to be unlocked and the wiper blade to be easily slid off the wiper-arm end in the direction of the vehicle windshield. However, the wiper rod and the preformed finger are made of flat coiled stock, the material thickness determining the small size of the lateral guide surfaces, and have a low moment of resistance in response to bending and torsion.

SUMMARY OF THE INVENTION

[0007] According to the present invention, the u-shaped cross-section profile of the hinge member extends to the free end of the wiper rod, and individual crosspieces are formed in the end region. In side flanges of the cross-section profile lying across from one another, at least one of these crosspieces of at least one crosspiece pair has a flap angled toward the inside, a retaining spring engaging between the crosspieces of a pair of crosspieces with a plug pointing in the longitudinal direction, and locking into place on the wiper rod. Due to the continuous u-profile, the hinge member designed in one piece with the wiper rod, has an advantageously high bending and torsion rigidity, as a result of which the wiper blade is guided across the vehicle windshield at a relatively constant setting angle, regardless of the operating conditions, resulting in good wiping outcomes. Because of the increased bending and torsion rigidity of the u-profile, the sheet metal thickness may be reduced if necessary, so that the weight and the material cost of the wiper arm are also reduced.

[0008] Furthermore, the production is simplified and costs are saved, since the hinge member is produced from one sheet metal cut in two bending steps and possibly one calibration step. At the same time, other regions of the wiper arm may be produced during the bending of the edges of the metal sheets, such as the areas that are later required for attaching the extension spring. The bending angle is never larger than 90° in any region, so that no extreme deformations occur and no danger exists that the protective layer of the coated materials detaches or tears at the bending points. Therefore, galvanized sheet metal panels or also other materials, such as aluminum, may be used without any problems.

[0009] On the hinge member, the lateral outer surfaces of the crosspieces and the adjoining u-shaped wiper rod form larger guide surfaces with respect to the retaining spring than known wiper rods having a hook-shaped end. Furthermore, the guidance is improved by the plug, which engages with the cavity between the crosspieces of a crosspiece pair by a slight slide fit or press fit, thereby simultaneously creating a sturdy connection between the retaining spring and the wiper rod. The improved guidance of the wiper blade has a positive effect on the wiping quality, in particular by reducing the rattling tendency of the wiper blade when little moisture is present on the vehicle windshield. Since numerous variations are possible, not only many known, but also many new applications may be covered.

[0010] In order to secure the retaining spring between the crosspieces in the axial direction, it is provided with a stop spring, which, in the mounted state, locks into the front side of a crosspiece or a flap. To disassemble the wiper blade, the riveting pin of the wiper blade may be pulled out of the open hub of the retaining spring, or the wiper blade may be disassembled from the wiper rod together with the retaining spring. For this purpose, the wiper blade is slightly rotated with respect to the wiper arm, which suffices to reach and disengage the stop spring. The wiper blade is then slid in the longitudinal direction until the crosspiece pairs on the wiper rod slide off the plugs. In a last disassembly step, the retaining spring may be pulled vertically out from the wiper arm.

[0011] The assembly is done in the reverse order and is also easily accomplished in only two directions by an automatic detent device; no additional tools are required. In this manner, an incorrect assembly of components or scratching by the use of unsuitable tools are avoided. In the described assembly or disassembly, the retaining spring may be preinstalled on the wiper blade and exchanged together with the wiper blade, so that a material may be used that is less prone to wear and approximately guarantees the service life of the wiper blade. It may also be premounted on the wiper rod and must have a correspondingly longer service life, which is assured by a longer-wearing material.

[0012] It is also possible to use this approach in windshield wipers having a continuous design, since no openings are required as mounting aids, and the wiper arm covers most of the retaining spring and the opening in the center clip toward the exterior.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Further advantages result from the following description of the drawings. The drawings show exemplary embodiments of the present invention. The drawings, the specification and the claims contain numerous features in combination. One skilled in the art will examine the features not only individually, but also combine them to meaningful combinations.

[0014] The figures show:

[0015]FIG. 1: a wiper rod having a hinged wiper blade;

[0016]FIG. 2: an end region of a wiper rod according to the present invention, viewed from above, in comparison to a known wiper rod;

[0017] FIGS. 3-5: an end region of a wiper rod according to the present invention, viewed from below, in comparison to a known wiper rod, a section along a line VI-VI in FIG. 2;

[0018] FIGS. 7-9: variants of FIG. 6;

[0019]FIG. 10: a perspective representation of an end region and a crosspiece pair;

[0020] FIGS. 11-16: variants of FIG. 10;

[0021]FIG. 17: a perspective representation of a retaining spring, viewed from above;

[0022]FIG. 18: a longitudinal section through a retaining spring;

[0023]FIG. 19: a step-by-step disassembly of a retaining spring; and

[0024]FIG. 20: a perspective representation of a wiper blade and a wiper arm during assembly and disassembly, respectively.

Description of the Exemplary Embodiments

[0025] A wiper blade 12, made up of a bracket assembly 14 and a wiper strip 16, is rotatably connected to a wiper rod 10 via a hinge, so that wiper strip 16 may adapt to the differently curved contour of a vehicle windshield 18 during the wiping movement (FIG. 1). The hinge is provided with a hinge pin 20, which is located on bracket assembly 14 and locks into place in an open hub 66 of a retaining spring 22 formed by feather tongues 80.

[0026] Wiper rod 10 has a u-shaped cross-section profile, which, according to the present invention, extends to the free end. At this free end, crosspiece pairs 38 and 40, which have a clearance 58 with respect to one another, are punched from side flanges 32 and 34 of the u-shaped cross-section profile. At each free end of a crosspiece of a crosspiece pair 38, 40, flaps 44, 46 are premolded, which are bent toward the inside at an approximately 90° angle and thus extend approximately parallel to top wall 42 of the u-shaped cross-section profile. Crosspiece pair 38 and 40, respectively, top wall 42 and flaps 44, 46 surround a cavity 94 that is open in the longitudinal direction (FIG. 2).

[0027] The u-shaped cross-section profile of wiper rod 10 is produced from a flat sheet metal piece, which is generally punched from a galvanized sheet metal panel. Side flanges 32, 34 having crosspieces 38, 40 and flaps 44, 46 are bent at a right angle to top wall 42 (FIG. 3). In a further bending step, flaps 44, 46 are bent an additional 90° with respect to the crosspieces. According to FIGS. 2 through 5 and FIGS. 11, 12, 15, the crosspieces of crosspiece pairs 38 and 40 each have a flap 44 and 46 on the same side flange 32 in each case, which extends parallel to top wall 42 and reaches up to the respective crosspiece of the other side flange 34 located across from it, while flaps 44 and 46 of crosspiece pairs 38, 40, in the embodiment according to FIG. 13, are assigned different side flanges 32, 34. FIG. 8 and FIG. 9 show short flaps 44 starting from crosspiece pairs 38 lying opposite one another and forming a small gap in the center between the crosspieces. Clearance 58 between crosspieces 38 and 40 is formed by a cut-out 36 in the sheet metal part (FIG. 3). It may be dimensioned in accordance with the requirements of the particular application case. Furthermore, height 88 of side flanges 32, 34 is reduced in front of retaining spring 22, facilitating the assembly of retaining spring 22. Crosspiece pairs 38, 40 and flaps 44, 46 are used to attach retaining spring 22 on wiper rod 10 (FIG. 17). Retaining spring 22 has two side walls 76 and 78, which are connected by an open hub 66, and a front wall 68 at the end of retaining spring 22. Between side walls 76 and 78, two plugs 70 and 74 extend in the longitudinal direction of retaining spring 22, one plug 70 being connected at one end to front wall 68, and the other plug 74 being connected at one end to hub 66. Between the free end of first plug 70 and hub 66 is an assembly shaft 72. For assembly purposes, crosspiece pair 40 is introduced into assembly shaft 72 and then slid axially onto plug 70 together with flap 46, while crosspiece pair 38 with flap 44 glides over plug 74. In the assembled state, plug 70 will then engage with a slight pressure fit or sliding fit in cavity 94 of crosspiece pair 40, front wall 68 being used as stop (FIG. 18).

[0028] Retaining spring 22 has a stop spring 82 at plug 74, which automatically locks into place at flap 44 of crosspiece pair 38, so that retaining spring 22 is connected to wiper rod 10 in a self-locking manner. Stop spring 82 may also be located at some other area of retaining spring 22, so that it locks into place, for example, at the edges or the front sides of crosspiece pairs 38, 40, or in stop holes 52 (FIG. 10) and stop notches, respectively. In order to ensure that there is no play in the mounting in the lateral direction, a tensioning element 86 is provided, which is formed on plug 74 and is supported at an axial stop 84 of wiper rod 10, so that retaining spring 22 is prestressed between stop spring 82 and tensioning element 86. Tensioning element 86 may also be arranged in such a way that it is supported on stop 62, 64 (FIG. 15, FIG. 16). Stop 62 is located on top wall 42, stop 64 at a crosspiece pair 40. Furthermore, a stop may also be formed by a collar 60, which is preformed on top wall 42 (FIG. 14).

[0029] The wiper according to the present invention provides good guidance of wiper blade 12. On the one hand, this is the result of the rigid and torsionally stiff u-shaped cross-profile being designed in one piece up to the area of the retaining spring, so that wiper rod (10) has a greater bending and torsion stiffness in an area 50 (FIG. 5) than the usual hook-shaped end 24 of a known wiper rod 26. Furthermore, additional component parts may be accommodated in the elongated building space, in particular in an area 48 of the open cross-section profile (FIG. 4) between side flanges 32, 34, such as water lines or spray nozzles of a windshield-washer system. On the other hand, compared to lateral guidance surfaces 30 of known wiper rod 26, large lateral guidance areas 28 (FIG. 2) advantageously result from crosspiece pairs 38, 40 and the adjoining parts of side flanges 32, 34, which may be adapted to the given operating conditions. Large guidance areas 28 lower the specific load of the contact surfaces between wiper rod 10 and retaining spring 22, so that the wear is low and the guidance quality during the service life of the windshield wiper is maintained.

[0030] The guidance and joining of retaining spring 22 are also supported by plugs 70, 74, which engage with the cavities 94 between the crosspiece pairs 38, 40. In this manner, one crosspiece pair 40 is sufficient for applications with a low load (FIG. 10). A stop hole 52 or a release 54 (FIG. 9) may be used to lock retaining spring 22.

[0031]FIG. 12 shows a variant in which an additional crosspiece pair 56 is provided, which is located in front of first crosspiece pair 38 and additionally guides wiper blade 12 (FIG. 12). This results in a particularly long guidance of wiper blade 12 in the longitudinal direction.

[0032] Compared to known wiper rod 26 (FIG. 3), wiper rod 10 does not have any angled regions with bending angles of 180°, but only of maximally 90°, thereby avoiding substantial material deformations and damage of protective layers resulting from these.

[0033] Due to the numerous variants for designing the cross-section of crosspieces 38, 40 and flaps 44, 46, which may also be combined with one another, it is possible to accommodate many already existing retaining springs 22 and to cover a large number of application cases.

[0034] Wiper rod 10 covers retaining spring 22 nearly completely towards the outside and is arranged with its free end and retaining spring 22 between the lateral walls of a center clip of bracket assembly 14, resulting in a continuous design with wiper blade 12. In order to change wiper blade 12, hinge pin 20 is pulled out from open hub 66, or wiper rod 10 is slightly rotated with respect to wiper blade 12, stop spring 82 also projecting beyond wiper 12 and being able to be unlocked (FIG. 19 and FIG. 20). Wiper rod 10 is then shifted in direction 90. In doing so, crosspiece pair 40 reaches into assembly shaft 72, while crosspiece pair 38 slides off plug 74. Wiper rod 10 is then removed from retaining spring 22 by a vertical movement in direction 92. Therefore, it is basically possible to either premount retaining spring 22 on hinge pin 20 of wiper blade 12 or on wiper rod 10. 

What is claimed is:
 1. A windshield wiper comprising a wiper arm of a mounting part and a hinge member having an integrated wiper rod (26), which has a u-shaped cross-section profile and to which a wiper blade (12) is coupled via a retaining spring (22), the side walls (76, 78) of the retaining spring (22) being connected by an open hub (66) for a hinge pin (20) and, by their projecting inner sides, guiding the wiper rod (10) on the outside, wherein the u-shaped cross-section profile extends to the free end of wiper rod (10) and formed in the end region in opposite side flanges (32, 34) of the cross-section profile is at least one crosspiece-pair (38, 40) of which at least one has a flap (44, 46) that is bent toward the inside; the retaining spring (22) engaging, by way of at least one longitudinally oriented plug (70, 74) between the crosspiece of a crosspiece pair (38, 40) and locking into place on the wiper rod (10).
 2. The windshield wiper as recited in claim 1, wherein the flap (44, 46) is provided with a stop hole (52).
 3. The windshield wiper as recited in one of the preceding claims, wherein, beginning at a front side at the end of the wiper rod (10), an angled stop (60, 62, 64) is preformed on the top wall (42), on a crosspiece of the crosspiece pair (40) or on the flap (44, 46).
 4. The windshield wiper as recited in claim 1, wherein at the end of the wiper rod (10) two crosspiece-pairs (38, 40) are provided, which have a clearance (58)with respect to one another.
 5. The windshield wiper as recited in one of the preceding claims, wherein the side flanges (32, 34) of the u-shaped cross-section profile have a reduced height (88) in front of the first crosspiece-pair (38).
 6. The windshield wiper as recited in claim 1, wherein the flaps (44, 46) on different crosspiece-pairs (38, 40) are preformed on the crosspieces located on the same side flange (32, 34).
 7. The windshield wiper as recited in one of the preceding claims, wherein the flaps (44, 46) on different crosspiece-pairs (38, 40) are preformed alternately on one crosspiece of the one side flange (32) or of the other side flange (34).
 8. The windshield wiper as recited in one of the preceding claims, wherein at least one plug (70, 74)of the retaining spring (22) is-connected to an end face of a front wall (68) at the end of the retaining spring (22) or to the hub (66).
 9. The windshield wiper as recited in one of the preceding claims, wherein the retaining spring (22) between the front wall (68) and the hub (66) has at least one transversely running assembly shaft (72)through which a crosspiece-pair (38, 40) of the wiper rod (10) is guided during assembly.
 10. The windshield wiper as recited in one of the preceding claims, wherein the retaining spring (22) is provided with a stop spring (82), which locks into place at an end face of a crosspiece (38, 40) or at a flap (44, 46).
 11. The windshield wiper as recited in one of the preceding claims, wherein the retaining spring (22) is supported on an axial stop (62, 64, 84) on the wiper rod (10), via a tensioning element (86).
 12. The windshield wiper as recited in one of the preceding claims, wherein the retaining spring (22) is premounted on the wiper rod (10).
 13. The windshield wiper as recited in one of the preceding claims, wherein the retaining spring (22) is premounted on the wiper blade (12). 